Articles formed from nucleated polyethylene

Abstract

Polymer articles and processes of forming the same are described herein. The processes generally include providing an ethylene based polymer, blending the ethylene based polymer with a modifier to form modified polyethylene and forming the modified polyethylene into a polymer article, wherein the polymer article exhibits a haze that is at least about 10% less than a polymer article prepared with a similarly modified polyethylene.

1. A process of forming a polymer article comprising:
 providing an ethylene based polymer, wherein the ethylene based polymer exhibits a density of from about 0.920 g/cc to about 0.970 g/cc and wherein the ethylene based polymer is formed from a catalyst system selected from a metallocene catalyst comprising tetrahydroindenyl ligands and a Ziegler-Natta catalyst formed by contacting a magnesium dialkoxide compound with successively stronger chlorinating agents; 
 blending the ethylene based polymer with a modifier to foam modified polyethylene, wherein the modifier is a nucleator comprising zinc stearate and a cyclohexane dicarboxylic acid calcium salt; and 
 forming the modified polyethylene into a polymer article. 
 
     
     
       2. The process of  claim 1 , wherein the modified polyethylene comprises from about 50 ppm to about 3000 ppm modifier. 
     
     
       3. The process of  claim 1 , wherein the ethylene based polymer comprises at least about 90 wt. % polyethylene. 
     
     
       4. The process of  claim 1 , wherein the ethylene based polymer comprises at least about 98 wt. % polyethylene. 
     
     
       5. The process of  claim 1 , wherein the ethylene based polymer comprises a melt index (MI 2 ) of less than about 15 dg/min. 
     
     
       6. The process of  claim 1 , wherein the forming comprises solid state stretching. 
     
     
       7. The process of  claim 1 , wherein the forming comprises blowing the modified polyethylene into a film. 
     
     
       8. The process of  claim 1 , wherein the ethylene based polymer exhibits a density of from about 0.926 g/cc to about 0.940 g/cc. 
     
     
       9. The process of  claim 1 , wherein the ethylene based polymer exhibits a density of from about 0.940 g/cc to about 0.970 g/cc. 
     
     
       10. The process of  claim 1 , wherein the forming comprises casting the modified polyethylene into a film. 
     
     
       11. The process of  claim 1 , wherein the forming comprises blow molding the modified polyethylene into a blow molded article. 
     
     
       12. The process of  claim 1 , wherein the ethylene based polymer exhibits a molecular weight distribution of from about 1.5 to about 7.0. 
     
     
       13. A polymer article formed from the process of  claim 1 . 
     
     
       14. The polymer article of  claim 13  comprising a blown. 
     
     
       15. The polymer article of  claim 13  comprising a cast film. 
     
     
       16. The polymer article of  claim 13  comprising a blow molded article. 
     
     
       17. The process of  claim 1 , wherein the polymer article exhibits a haze that is at least about 35% less than a polymer article formed by a substantially identical process and polymer absent the modifier. 
     
     
       18. The process of  claim 1 , wherein the polymer article exhibits a gloss that is at least about 50% higher than a polymer article formed by a substantially identical process and polymer absent the modifier. 
     
     
       19. The process of  claim 1 , wherein the polymer article exhibits a water vapor transmission rate that is at least about 20% less than a polymer article formed by a substantially identical process and polymer absent the modifier. 
     
     
       20. The process of  claim 1  further comprising blending the modified polyethylene with a second ethylene based polymer.